Drain arrangement for floating roof



Oct. 21; 1958 v R. w. BODLEY 2,857,072 I DRAIN ARRANGEMENT FOR FLOATINGROOF.

Filed May 21. 1956 3 Sheets-sheaf l i r J 32// C3 rfiio 38 1 INVENTOR.

Oct. 21, 1958 R. w. BODLEY 2,857,072

mum QARRANGIEMENT'FOR FLOATING ROOF Filed May 21, 1956 Y s Sheet-Sheet-2 INVENTOR.

United DRAIN ARRANGEMENT FOR FLOATING ROOF Application May 21, 1956,Serial No. 586,050

12'Claims. (Cl. 220-26) The invention relates to floating roof tanks andmore particularly to a novel and improved drain arrangement therefore.

As is well known in the art, floating roof tanks are usually employed tostore volatile liquids, such as petroleum products, where the purpose isto control and minimize product losses due to evaporation. of tank, acircular shell having an open top is provided. To close the top, theroof is arranged to floaton the stored product and consequently risesand'falls in response to a change in the'level of the product within thetank. At the normally high position the floating roof is just below thetop edge of the tank. The roof may be additionally provided withdepending legs which are secured to the under side of the roof, saidlegs supporting the roof in spaced relation to' the tank bottom whenmost or all of the product is drainedfrom the tank. It is obvioustherefore, that the position of the roof will vary between the mentionedmaximum and minimum positions depending on the level of the product inthe tank. Floating roofs are of varying types, but, in the usualinstance, are saucered when seen in side elevation, to afford the'necessary buoyancy. -In some instances pontoons are added to the roof toprovide additional buoyant effect. Because of the form of the roof, itwill naturally collect rainwater and other foreign matter that fallsthereon and it is usual toprovide, at a low point on the roof form, asump orthe like to which the rain water'will drain due to pitch of theroof. In order to preserve the stability and buoyancy of the roof, thecollected rain Water must be drained therefrom and this is usuallyaccomplished by providing a conduit communicating with the sump-andextending downwardly therefrom into the tank, through the product storedtherein to some outlet point on the tank shell, whereat the conduitcommunicates with a nozzle or drain to carry away the water.

The conduit employed may be of several types, one of them being aflexible hose drain. In some instances a plurality of sections of rigidpipes having pivotal connections intermediate the sump and outlet arealso em ployed. I

It is thought obvious, that in order to satisfactorily drain water fromthe roof, a gradient from sump to outlet should be maintained duringmost positions of the roof in the tank. It has been found that the drainconduit frequentlybecomes fouled in the tank destroying the requiredgradient or blocking the conduit passageway and thus preventing properdrainage of the water from the roof. Where the conduit is allowed tomove freely in the tank, it may, for example, become fouled with thelegs on the underside of the roof or, in the case of a flexible conduitbecome tangled in itself, thus interfering with or prohibiting properdrainage.

In order to prevent any of the above mentioned difficulties thedisclosed invention provides an improved arrangement having guide meansassociated therewith that will control movement of the hose drain orflexible conduit in such a manner that proper drainage is assured.

In this form atent Patented Oct. 21, 1958 It is a specific object of theinvention to provide a controlling cable having one end thereof securedto the hose drain intermediate the ends of the latter, and the other endthereof secured to the tank shell and arranged to coact with floatingroof whereby movement of the roof will cause the cable and connecteddrain to move in a predetermined pattern.

These and other objects of the invention will become apparent in thecourse of the following description and from an examination of the,concerned drawings wherein:

Figure 1 is a plan view ofa tank incorporating the invention,

Figure 2 is a side elevational view, partly in section, illustrating thestructure of Figure 1,

Figure 3 is an-enlarged, fragmentary sectional view showing theconnection of the cable to the tank shell,

Figure 3A is a sectional View taken along line 3A3A of Figure 3,

Figure 4 is a side elevational view of a modified embodiment of theinvention,

tank comprises a shellfwhich is usually cylindrical in form, and a roof6 positioned therein andslightly smaller in diameter than the shell 4,whereby the roof may move vertically in the tank in response to thechange in product level. Around the periphery of the roof a conventionalseal mechanism (not shown) may be employed, as is familiar to thoseskilled in the art. The tank-additionally may be provided with a windgirder 8 arranged to encircle the outer shell adjacent the top thereofto-provide the proper tank rigidity or resistance to damage due to windimpinging on the shell surface. 7

Directing attention to Figure 2, it will be seen that the roof is shownin low position whereat a plurality of legs 10, secured to the underside of roof, abut the'tank bottom and locate the roof in spacedrelation thereto. The roof is shown in phantom at 6a in-the highposition whereat it is immediately adjacent the top edge of the tankshell 4. As earlier noted, the roof 6 is'provided with a centrallylocated sump 12, said roof beingpitched toward thesurnp from alldirections, whereby collected water on the roof will drain toward thesump. A hose or conduit 14 is connected to and communicates at one end16 to the sump 12. The other end of the hose 14 is connected to andcommunicates with a nozzle 18 in the tank shell 4, preferably adjacentthe bottom thereof. 7

Considering Figures 2 and 3, it will be seen that the design provides abracket 20 secured to the tank shell 4 proferably at the top edgethereof. The bracket20 has an arm 22 which extends inwardly of "the tankshell to overlie a portion of the roof. At the inner end of the arm acable connection 24-, such as an eye bolt and nut ately below theaperture 28 a cable guide 32 is secured,

to the under side of the roof. In the preferred embodiment the guidecomprises a cylindrical element 36 having enlargedfl-anges, 38, 38 onopposite sides thereof.

The cable 26 engages the guide 32 and extends inward- I 1y of the tankto connect) to the hose 14, as at 40, at a point intermediate theends-of the hose. A weight 42 is Figure 5 is a plan view of thestructure shown in Fig-.

:7 3 secured to the cable 26 at a point in spaced relation to theconnection 40, said weight keeping the desired tension in the cable 26during the action hereinafter described, and also assuring that thecable will movein a generally constant vertical path. I

Considering the operation of the disclosed invention the roof will beconsidered in the high position shown at 6a in Figure 2. In thisposition thecable 26 and the weight 42 are in elevated position in thetank, and the hose 14 extends downwardly between the sump 12 and theoutlet 18. As the roof descends in response to product evacuation, thecable 26 in engagement with the guide 32 pulls the hose 26 toward theshell of the tank. At its low position the hose 14 has the upper andlower portions thereof bent in acute angle relationship to each other,as seen in Figures 1 and 2. It will also be noted that the action of thehose 26 is controlled at all positions of the floating roof in the tankthereby precluding any possibility that the hose will entangle in itselfor in the supporting legs 10 during roof action, thereby preventingproper drainage. It will be particularly understood that the connection40 between the cable and the hose may be a conventional collarconnection (not shown) which will prevent any sharp restrictive bend inthe hose at this point.

Figures 4 and 5 show a slight modified embodiment of the inventionadapted to a high tank having a relatively small diameter. In thisembodiment structure identical with that heretofore described isindicated with identical numerals. In general, the increased height ofthe tank and the consequent necessity of having a relatively longer hosedrain requires that the arrangement employ a plurality of guide cableswhich, in low position of the roof, form the cable into an S-shape ormultiple angular shape similar to the preceding embodiment. A pluralityof cables 62 are here provided, each having a connection to the hose 60at spaced points thereon. The upper ends of the cable 62 are secured tothe top of the tank shell in a manner similar with the cable 26 of thepreceding em- 'bodiment and at spaced points 64, 64 on said tank shell.As the roof descends in the tank 4, the cables 62 operatively engage theroof as illustrated in Figure 3. The movement of the roof urges the hose60 into a predetermined folded relationship as shown due to theconnection between the cables 62 and the'hose 60. It will be noted thatthe hose forms a generally S-shaped fold when the roof is in the lowposition and as seen in both the side elevational view of Figure 4 andthe plan view of Figure 5.

Considering the embodiment of Figures 6 and 7, it will be noted that thestructural features which are physically similar and identical infunction with the features of the previous embodiments, are again givenlike numerals. It will be seen that the embodiment here employs a hosedrain 14a which may be connected to the central sump 16 and the outletnozzle 18. A flexible cable 26a connects at 40a with an intermediateportion of the hose 14a, said cable extending upwardly through anaperture 28 in the roof Whereat it operatively associates with a pair ofpulleys 22a mounted on the tank shell bracket 20a. A weight 42a isconnected to the outer extremity of the cable 26a and is free to movevertically a determined distance in response to the action of the cableas hereinafter described. In this embodiment, as the roof 6 descendsfrom its maximum upper position, the cable 26a again urges the hosedrain 14a to follow a predetermined pattern of movement. During theinitial lowering movement of the roof, the weight 42a occupies its lowerposition, shown in phantom at the left hand portion of Figure 6.However, as the roof continues to descend and reach a predeterminedpoint, the cable 26a has acted to pull the hose drain 14a to adetermined angled condition. At this point the cable 26a iscomparatively taut, and continued lowering movement of the roof cannotbe accommodated by horizontal movement of the hose drain 14a. Thereforecontinued lowering movement of the roof may be accommodated by theelfective extension of the length of the cable 26a by virtue of theupward movement of the weight 4211 to its upper position, as shown insolid lines at the left hand side of Figure 6, which illustrates theposition of same when the roof has reached its maximum descendedcondition. In effect, there will be no movement of the weight duringinitial lowering of the roof,

but the weight will move and accommodate an operative lengthening of thecable 26 during the final stages of the lowering of the root. In thisembodiment, the location of the weight at the end of the cable 26a,positively prevents the hose 14a, or any portion thereof from beingdragged over the bottom of the tank during controlled movement thereof.Again, movement of the hose 14a is controlled to prevent fouling orother difficulties that may interfere with proper drainage.

Thus it will be seen that the invention provides a novel drainarrangement which remedies the difliculty heretofore found and simplyand easily assures a positive trouble free operation required instructures of this nature.

It will be understood that the above is by way of illustration and notlimitation and that the invention may be subject to variousmodifications without departing from the spirit thereof or the scope ofthe appended claims.

I claim:

1. In a drain arrangement, the combination of an open top tank shell anda roof arranged to float on product therein, a hose connected at one endto a sump on the roof and at the other end to a drain means externallyof the tank, guide means being fixedly connected to the hose at a pointintermediate the hose ends, said guide means having a direct operativeconnection to the tank shell, and other means operativelyinterconnecting the floating roof and the guide means whereby upondownward movement of the roof the guide means exert a generally lateralforce on the hose to move same ina predetermined manner in the tank.

2. A drain arrangement according to claim 1, wherein said hose isflexible and the guide means comprises a cable having one end fixedlyconnected to the hose and another end connected to the tank shell, saidcable operatively engaging the roof during movement of the latter.

3. A drain arrangement for a floating roof tank according to claim 2,and including a weight connected to the cable.

4. A drain arrangement according to claim 2, wherein said cableoperatively engages the roof in an area immediately adjacent theperiphery thereof.

5. In combination, a tank, a floating roof in the tank,

a sump centrally located on the roof to collect foreign p the tank shellbelow the roof, said hose drain being flexible throughout substantiallyits entire length, an aperture in the roof immediately adjacent the edgethereof, a flexible cable having one end in operative connection withthe tank and extending downwardly through the aperture, said cable beingdirected inwardly below the roof to a point where its other end isconnected to the drain intermediate the ends thereof, a pulley-likeelement on the roof and below the aperture and engaging the cable,whereby upon downward movement of the roof, said pulley-like elementoperatively engages the cable to exert a lateral movable force on thelatter whereby the hose drain is moved in a determined generallyhorizontal pattern in the tank.

6. In combination, a tank, a floating roof in the tank, a sump on theroof to collect foreign matter deposited on the roof, a flexible hosedrain communicating with sump and extending downwardly into the tank,said drain communicating with an outlet in the tank shell below theroof, at least one bracket mounted on the tank adjacent the upper edgethereof and above the roof, at least one tal direction and in adetermined pattern in the tank.

7. The combination of claim 6, and including weight means associatedwith the member.

8. A drain arrangement according to claim 7, wherein said operativeconnection between the guide member and bracket is a direct fixedconnection.

9. In a drain arrangement for a tank having a floating roof, a sump inthe roof, a flexible hose drain communicating with the sump andextending downwardly through the tank to an outlet, a plurality of guidecables having certain ends connected to the tank adjacent the upper edgethereof, said cables extending downwardly into the tank and having theirother ends connected to the drain at spaced points thereon, said cablesoperatively engaging the roof whereby downward movement of the latterurges the drain into a predetermined S-shaped pattern.

10. In a drain arrangement, the combination of an open top tank shelland a floating roof arranged to be supported on product therein, a hoseconnected at one 6 end to a central sump on the roof and at the otherend to drain means externally of the tank, guide means comprising agenerally flexible cable having one end thereof fixedly connected to thehose intermediate the ends of the latter, the other end of said cablebeing operatively and movably connected to the tank shell, and movableweight means operatively associated with the second mentioned end of thecable, said cable operatively engaging and coacting with the roofadjacent the periphery of the latter and during vertical movementthereof so that the cable exerts a generally lateral force on the hoseurging the latter to move in a determined generally horizontal patternin the tank.

11. A drain arrangement according to claim 10, wherein said operativeconnection between the tank shell and the cable comprises pulley meanson the shell operatively engaging the cable. p

12. A drain arrangement according to claim 11, wherein said weight meansis operative to move only during certain portions of the movement of theroof.

References Cited in the file of this patent UNITED STATES PATENTS

